1. Field of the Invention
The present invention relates to an optical disc, and more particularly, to a method of allocating areas in an optical disc, a data recording and/or reproducing apparatus adopting the same, and an optical disc therefor.
2. Description of the Related Art
In general, optical discs are classified into compact discs (CDs) and digital versatile discs (DVDs) according to a recording capacity. Kinds of optical discs, on which data can be recorded, erased from and reproduced from, include 650 MB CD-R, 650 MB CD-RW, 4.7 GB DVD+R/RW, 4.7 GB DVD-RAM, and DVD-R/RW optical discs. Kinds of read-only optical discs include 650 MB CD and 4.7 GB DVD-ROM discs. Furthermore, a next generation DVD having a recording capacity of over 15 GB is under development.
In a case of a conventional recordable DVD, there are only 4.7 GB single layer discs. However, in a case of a DVD-ROM, there are already 8.5 GB dual layer discs. In order to backup these 8.5 GB discs, an 8.5 GB recordable DVD is required. However, in this case, since a recording time basically doubles, it can be a disadvantage for a user. A method of improving the recording speed would be desirable. However, since improvement of disc technology must precede such an improved method, a method of effectively recording data at a conventional speed is required to immediately introduce the 8.5 GB recordable DVD to the market.
FIG. 1A illustrates a structure of a conventional rewritable optical disc. FIG. 1B illustrates a structure of a conventional read-only optical disc. A structure of a lead-out area of the rewritable optical disc shown in FIG. 1A is almost the same as a structure of a lead-in area. In particular, the lead-in area of the rewritable optical disc shown in FIG. 1A includes a test area used to determine an optimal recording power.
FIGS. 2A and 2B illustrate structures of dual recording layer discs on which data is recorded in a disc-at-once mode. The disc-at-once mode is a recording mode in which data is recorded on a disc at once (i.e., in a single recording session) and a predetermined pattern of data is recorded on an empty data area, in which data is not recorded, so as not to record additional data on the disc even if the empty data area remains. In general, the disc-at-once mode is used to produce backups of bulk data by recording the bulk data on write-once discs.
On a dual recording layer optical disc 10 shown in FIG. 2A, data is recorded in an opposite track pass (OTP) direction, and on an optical disc 20 shown in FIG. 2B, data is recorded in a parallel track pass (PTP) direction.
Referring to FIG. 2A, when data is recorded on the dual recording layer optical disc 10 in the disc-at-once mode in the OTP direction according to conventional technology, user data is recorded in a data area 12 of a recording layer L1 from which layer the data is firstly reproduced, and remaining user data is recorded in a data area 15 of a recording layer L2. Areas 13 and 14 located outside an outer boundary 19 of the data areas 12 and 15 are fully occupied with a predetermined pattern of data for indicating no data areas. The predetermined pattern of data, for example, is data having a lead-out attribute. An area occupied with the predetermined pattern of data for indicating the no data area is commonly called a connection area to discriminate from a lead-in area 11 and a lead-out area 17.
An empty area 16, in which the user data is not recorded, of an entire data area of the recording layer L2 becomes the connection area by being occupied with the predetermined pattern of data for indicating the no data area.
The optical disc 20 shown in FIG. 2B includes a lead-in area 21, a data area 22 of a recording layer L1, a lead-out area 24, a data area 25 of a recording layer L2, and connection areas 23 and 26 of the recording layers L1 and L2.
Recording methods illustrated in FIGS. 2A and 2B are applicable to read-only discs and rewritable discs in the same way.
In the methods of recording data on an optical disc in the disc-at-once mode according to the conventional technology described above, an additional data recording time is required to record the predetermined pattern of data having the lead-out attribute in the area on which the user data is not recorded. Furthermore, since the areas outside the data areas are not used at all, optical discs are not efficiently used.